Single blade plow



y 1948- I H. MAXIM ETAL 2,440,905

SINGLE BLADE PLOW Filed May 20, 1946 2 Sheets-Sheet 1 INVENTOR5 H/MMH/VM/MA/w [Eu/E ZZMAPP 6 94030 ad ATTORN Ys H. H. MAXIM ETAL f 2,440,905

SINGLE BLADE PLOW Filed May 20, 1946 2 Sheets-Sheet 2 5% llll/ May 4, 1948.

Patented May 4, 1 948 Hiram H. Maxim,

Hartford, and Leslie E. Knapp,

Wethersfield, Conn., assignors to The Maxim Silencer Company, tion of Connecticut Hartford, Conn, a corpora- Application May 20, 1946, Serial No. 670,878

1 Claim. (01. 37-42) This invention relates to single bladed snowplows, particularly such as are attachable to automobiles, tractors and the like. I

One object of the invention is to provide a plow of this general type with improved mechanis'm for freeing the plow blade automatically from obstructions over which it may pass, without injury to the plow or to the obstruction. A further object is to provide a plow with improved mechanism which will return the plow blade to normal position after clearing the obstruction. A further object is to provide a plowthe blade of which will tip forwardly and rise automatically on striking a surface obstruction but which will not be affected by heavy pressure against the snow being plowed. A further object is to provide a single blade plow with simple mechanism. by which it may be raised to avoid dragging snow backwardly when the car or tractor is being backed up. A further object is to provide a single bladed plow with mechanism for attaching the plow to the bumper of an automobile, adjustable for different makes of car and readily changed to set the plow at the desired angle and hand. Other objects will appear fromthe following description and claim.

Referring to the drawings,

Fig. 1 is a top plan view of a plow constructed in accordance with our invention;

Fig. 2 is a rear view thereof;

Fig. 3 is a section on line '3-3of Fig. 2;

Fig. 4 is a section on line 4-4 of Fig. 2;

Fig. 5 is a section generally similar to Fig. 3 but showing the action of the plow in clearing an obstruction: and

Fig. 6 is an end view sociated parts.

The plow comprises a curved moldboard blade I the top edge of which is preferably turned back at 2 to form a reinforcement. An angle 3, forming both a runner and a reinforcement, i secured as by welding to the bottom edge of the moldboard. End plates 4 welded to the ends of the moldboard and of the angle 3, and intermediate plates 5 similarly welded, provide the necessary rigidity for the moldboard.

Pivotally bolted at 6 to the intermediate plates *5 is a semicircular sector I, the pivot axis 6-6 being relatively low on the moldboard for a purpose to be described. A second sector 8 of lesser extent is mounted to swing about the axis of sector 1 upon a pivot bolt 9, and is held in any desired angular position by a pin I 0 passing through a hole in sector I and an aligned hole II in one of two brackets 12 welded to it and also through a of the moldboard and asselected one .of a series of holes l3 in sector 8. The sector 1 being secured to the moldboard as described above, and also connected by a thrust frame to the automobile bumper as described below, the moldboard can be freed for adjustment of its plowing angle by withdrawing the pin 10 and locked in the position selected by replacing it.

Also mounted to swing on pivot bolt 9 are a pair of angle irons each having a horizontal leg l4 bolted at l5 through one of a series of holes IS in the sector 8 and a vertical leg I! having a series of holes l8 arranged concentrically about a bolt l9. Mounted on bolts l9 are angle irons secured at any desired vertical angle by bolts 2! passing through selected holes I 8. The ends of the angles 20 are provided with plates 22 welded in place and bolted plvotally at 23 to an angle 24 having a vertical extension 25 adapted to lie against the front of the bumper 2B of an automobile. Each vertical plate 25 is provided with a hole for a hook bolt 21 to engage the lower edge of the bumper and with a hook bolt 28 to engage the upper edge of the bumper and having a sleeve nut 29 by which it may be tightened. This type of bumper clamp is described in detail and claimed in the copending application of Maxim and Bourne, Serial No. 670,874, filed May 20, 1946. A brace 30 formed of overlapping bars on angles 3| bolted together at 32 through a series of holes 33 gives :lateral rigidity to the parts previously described. In fact, when the adjustments have all been made and the bolts tightened, the structure is substantially a rigid truss 34 pivoted to the bumper at spaced points and to the lower portion of the moldboard so that the latter may rise and fall with the contour of the ground but with the thrust always directed forwardly and downwardly by the truss to keep the moldboard against the ground during plowing.

As thus far described the moldboard is unconnected to the truss except at a pivot axis below its center. In order to have the moldboard held substantially rigid during plowing and yet free to swing forwardly about its pivot to clear itself from obstacles in a manner which will be explained, a yieldable strut is provided. To a bracket 35 welded adjacent the top of the moldboard at its center is pivoted a rod 36 having a head 31 at its rear end which reciprocates like a piston in a cylinder 38 pivoted at 39 to a bracket 40 secured as by welding to the vertical wall 4| of sector I. The angle irons 20 are adjusted by selecting the bolt holes I8 for the automobile with which the plow is to be used so that the rod 36 strikes the bottom of cylinder 38 when the moldof rod 36 with'the end of the cylinder 38. If the:

lower edge of the moldboard strikes a rigi cl ob; struction, however, so that the lower edge'cannot continue to advance, the boldboard as a urritimay tilt forwardly.

In prior constructions in which a -sprirrg'lfel'd, pivoted moldboard was used for this purpose, it

to the rear side of the moldboard. The distance between the pivot pin 50 and the shoe bottom is greater than the distance between the pin and the ground when the blade is in normal position. An angular plate 52, having bolt holes in both legs to permit reversal is bolted at 53 to the iront sidepf the shoe. ,Duringnonnai plowin the plate '52 drags on the ground as in Fig. 4, holding the shoe elevated. If the plow is drawn 'rearwardly, however, the plate digs in and holds the. shoe. initially from moving with the plow, so that-the blade is elevated until the bottom of the; shoeis flatppon the ground and the plate was necessary that it tip far enough forward so that the lower edge could slide over the assets: tion. board tilt so far that it was nearly fiat on the ground, resulting in its upper edge digging into thesnow so firmly that it wouldnot right itself unless moved backwards, We have provided a simplemeansby which tilting. of the moldboard causes its lower edge to be raised and freed without thenecessit-y :of tilting so far that it will slide over the obstruction, '-l','his means comprises a pair of generally semicircular hoops 44 welded tojthe moldboard not iarfrom its ends and projecting forwardly. As the lower edge of the moldboard strikes an obstructiomsuch asfio' in Fig.5, the upper-part of the moldboard will be pushed ahead, "compressing spring 43 and rolling the moldboard as a whole over on the hoops. This rolling action gradually lifts thelower edge of the moldboard s that it can clear the obstruction. Spring 43;,assisted by snow pressure on theplow; then returns themoldboard to nor mal position. The hoops are made-as narrow as is consistent with strength in order to otter as little resistance as possible to passage through the snow; and are set near the ends ot the moldboard to avoid a tendency, which existswhen the hoops are too far frorn the ends, of one end to dig-into the ground when the blade tilts. h

it is a further ieature of this plow that the blade is lifted clear of the ground whenever the plow is movedrearwardly. Each lifter comprises a shoe 46 having a flat bottom 41 and upturned sides 48 welded or otherwise .securedto :the: lower ends ofa pair of angle irons 49 vpivoteaiione. pin 58 securedina U-shaped bracket welded Frequently this required that the moldt .strikesfagainst'the rear of the mold-board. In

thispositiontheTplate 52 is clear of the ground and the p'lowslide's along on the two shoes 46 with thebiade raised so that no snow will be scrapdup between the blade and the pushing vehicle Thus the blade is automatically elevated either when an obstruction is encountered or hen sr wr s;m vedrearward r- The es is that much cleaner plowing pan bedone than with prior types of single blade plows.

s wppw pri in a: n oldbpant ase or pivoted to h mold o rd a horizo tal xis; a ssono eg e ,piv te t e fi st ctor one vertical axis, means ;to S l,1re,Sj tid sectors to.- gether in selectedpositions to adjust the plowin angle of the moldboard, a pair of members pivs ote'd on a vertical axis, means for securing said members in selected ."angular positions to the second: sector, struts pivoted to saidineiiibers and extending rearwardly',im'eans holdingthe struts to said members in adjusted angular position; a cross brace connecting said struts ma aajustat e in length to permit angular adjustment offsaid members and struts; and means for fcjon'nct'irig, saidstruts to a pushing'vhible.

I msua E. KN PP;

REFERENUES CITED s ,Th'eiollowin'" references are of said as file of this patent:

UNITED s'rnTEs PATENTS 5 Nimiber 

